Ribbon attachment for typewriters for making duplicate copies



y 1942- J. R. GESER 2,281,688

RIBBON ATTACHMENT FOR TYPEWRITERS FOR MAKING DUPLICATE COPIES FiledFA g. 8, 1959 5 Shees-Sheet J.

I .I. 3 .9 61 0 2 n i I? w I! I I l I WA W ,N

Hx I May 5, 1942. J. R 5553 2,281,688

RIBBON ATTACHMENT FOR TYPEWRITERS FOR MAKING DUPLICATE COPIES Filed Aug. 8, 1939 2 Sheets-Sheet 2 Patented 5, 1942 RIBBON ATTACHMENT FOB TYPEWRITERS FOR MAKING DUPLICATE COPIES Joaeflne Rosa Geser, Zurich, Switzerland Application August a, 1939, Serial No. 289,018 In Switzerland May 18, 1939 Claims. (Cl. 197153) The invention relates to a ribbon attachment for typewriters for making aduplicate copy. According to the invention at least one additional ribbon driven from the platen by means such as a friction roller is carried past the platten and can be swung into and out of writing position.

The invention comprises a number of novel features which, individually, as well as in combination make up the invention.

Friction drive rollers for the actuating mecha-- nism of the additional ribbon are. according to the present invention, forced against the platen by spring pressure. Mechanism for changing the direction of the additional ribbon is provided with a power storage device so that, on reversing the direction little power is necessary. This power is furnished through an auxiliary device, for releasing the power of the storage driver, whereby the additional ribbon is not subjected to unnecessary tension. Another feature of the invention consists in a specially constructed check device for preventing the additional ribbon from becoming slack when the platen is turned backward. Known devices for this purpose are defective in that they have more or less lost motion, that is, they do not enter into operation immediately when the platen is turned back. The check device of the present invention consists of a pawl in frictional connection with the platen. When the platen is turned forward, the pawl is released, but when it is turned backward, the pawl checks the mechanism which actuates the additional ribbon.

Other features of the invention will appear from the following specification.

An exemplary embodiment of the invention is illustrated in the drawings, in which:

Figure l is a front elevation of the apparatus as it appears when attached to a typewriter.

Figure 2 is a section through one of the two housings in which the ribbon supports are lo-' cated, the section being taken on line II-II of Fig. l, and with the apparatus in writing position.

Figures 2a and 2b show details-of Figure 2; 2b being taken on the line IIb-IIb of Fig. 2.

Figure 2c is an enlarged detail of Fig. 2b.

Figure 3 is a section similar to Fig. 2, showing other details, and with the apparatus in retracted position.

Figure 4 is a development in section of the front plate of one of the two housings in which the ribbon supports are mounted. the section being taken on line IV--IV of Fig. 3.

Figure 5 is a section through the axis of the shift bar, on line V--V of Fig. 3.

Figures 5a. and 5b are respectively side and face views of the tension key for one of the spring means employed.

Figure 6 is a plan view of Fig. 5.

Figure 7a is a face view of one of the mounting supports provided on the frame of the machine, looking in the direction of the arrow AI (Fig. 6); and

Figure 7b is a similar view of the other support looking in the direction of the arrow A2 on Fig. 6.

In the drawings reference character. I designates the typewriter platen provided at the ends with the usual rotating knobs la and lb. 2 designates the additional ribbon of the present invention which runs on the ribbon carriers 3a and 3b. The ribbon carriers are each provided with two clutch pins 4 which couple the carriers to gears 5 and are each mounted rotatably on a pin I attached to the housing 6 and retained thereon by a bayonet joint (not shown). 8 and 9 designate two paper guide rollers which are axially slidable in the usual manner on a bar ll. This bar is carried at its ends by rocker arms l'i disposed in the side wall of housing 6.

Inasmuch as the members mounted in housing 6 lie symmetrically with respect to a central plane of the apparatus, only those of one side are described in the following specification.

Figure 2 shows a pawl II which serves to prevent the additional ribbon 2 from becoming slack on reverse rotation of platen I. It isjournalled rotatably about the pin l3 and is frictionally connected with platen I. If the latter is rotated in r the direction of the arrow A! the pawl I2 is disconnected. If, on the other hand, the platen l is rotated in the direction of the arrow A4, that is, backwardly, the transmission of the platen causes the pawl part to engage the gear 5, whereby the actuating mechanism of the additional ribbon 2 is stopped, It designates a small auxiliary weight designed to hold pawl l2 in inoperative position.

In Figure 2, I5 designates a friction roller in frictional engagement with platen l. The roller is toothed and rotatably journalled on pin ii. The teeth of the friction roller mesh with the gear 5, which is coupled with the ribbon carrier in. The pin it is mounted in a rocking lever II which can describe a swinging movement about pin is in the direction of the arrow A5. Lever i1 is provided at its upper end with a pin ['9 which extends into a slot 20b of a shift member 20 adapted to rock about the pivot pin 2|. The pin ll of the rocking lever I1 is iournalled in a hookshaped cage 22 rotatably mounted on tube 23. The shift member 20 also has a shoulder 231 which, by means of a fixed tube 23 in which the shift bar'24 is disposed, eng es in a groove 24a in the shift bar and carries it along in the oscillating movement.

Figure 2c shows the shift member in both of its end positions, the full line indicating the position in which the friction roller I is held engaged with the gear 5 by the pin l8 controlled through the slot 20b, while the dotted line shows the position of the shift member in which the roller I5 is rocked in the direction of the arrow A5, and out of engagement with tooth crown of gear 5.

Figure 20 also shows the setting mechanism of the shift member 20 in its end position. It consists of a spring-actuated ball 25 which, in the end positions of the shift member, snaps into corresponding notches x1 and $2 in the shift member and retains it.

The pressure of the friction rollers i5 against the platen I is produced by the leaf spring 26 mounted in the cage 22, and is applied against one edge of the surface 23a provided on the tube 23 and thereby imparts to said tube 23, and the friction roller l5 positively connected with it, a tendency to rotate clockwise. The tube 23, in turn, is supported on the surfaces 49a of the support 46 (Fig. 7a) attached to the machine frame. The preliminary tension of the leaf spring 26 is produced by turning tube 23 by means of a key 28 until the edge of surface 23a bears against spring 26 (Figs. 5a and 5b) after the apparatus has been mounted on the typewriter as will be hereinafter explained.

A catch 28 (Fig, 2) is mounted in known manner at the ends of the additional ribbon 2. When the ribbon has run off carrier 31: or 3b to such an extent that the catch 23 strikes against the slot 301; of the head piece 30, the steel band 3| is moved in the direction of the arrow A6 (Fig. 4). A transverse bar 32 is pivoted by means of the pin 33 at the upper end of the steel band 3! (Fig. 4), and is rotatable about a pin 34 mounted rigidly in housing 6. In the downward movement of pin 33 the impact member 35 is drawn downwardly in the guide slot 35a by pin 33a. The knife edge 36 is rigidly connected with the impact member 35, and engages in the groove of the worm 31 and is drawn therefrom on the backward movement of the impact member 35. However, the member 35 is subject to the action of the spring 38, which tends'to throw it off in the directionof the arrow A1.

The storage spring 38 is tensed in the following manner. Assuming the spring to be relaxed, the knife edge 36 is at the right side of the worm 31 (Fig. 4) Housing 6 is rockedabout tube 23 during movement away from the writing position of Fig. 2 to that shown in Fig. 3. The shift wheel 39 is at the left end of the worm 31 (Fig. 4). Wheel 39, when housing 6 i folded back to the writing position (of Fig. 2), strikes against the pawl 40 oscillatably mounted in cage 22 and there tensions the accumulator spring 38, by means of the knife edge running in the worm groove, for one tooth division. Since, at each change of the paper, the apparatus is swung from the writing position at least once, and spring 38 each time tensioned through one tooth division, the accumulator mechanism can be completely tensioned by the time a change in the direction of travel of the additional ribbon is to take place. Any excess tensioning simply acts to rotate the means of the key 28 (Figs. 2, 2b and 5a) 2,2s1,ess

worm 31 without changing the location of'knife edge 33. The knife edge 33 engages the worm 31 as shown in Fig. 4. when the worm is rotated, the knife edge travels to the left and compresses spring 33. If the link 3| is pulled in the direction of the arrow A3, the knife edge 33 is disengaged from the worm and the spring 38 throws the knife edge, which is rigidly connected to the lever 35, to the right against pin 4| (Fig. 2) for producing reversal of the ribbon.

If, now, the impact member 35 is projected in the direction of the arrow Al by storage spring 38 it strikes in its path of movement, the pin 4| on shift member 20. Member 20 is then thrown to the dotted line position ofFig. 2c, the pin is moves outwardly in slot 20b, friction roller I5 is rotated in the direction of arrow A5 and thereby carried out of engagement with the tooth crown ofgear 5. At the same time the shoulder 20a of the member 20 moves the shift bar 24' backwardly, whereby, in housing 6, at the opposite side, the friction roller I5 is carried into engagement with the tooth crown of the gear 5 at that side. The additional ribbon 2 has now changed its direction of travel.

43 is a guide pin and 6a a reversing slot in the housing 8 for the additional ribbon (Fig. 4).

There are various methods of attaching the mechanism on the typewriter. It can be mounted directly on the machine frame or, as shown herein, it may be mounted in supports 45 and 46 (Figs. 7a and 7b) attached to the machine frame. Support 45 contains a circular opening 47 for the insertion of the tube 23, and the other frame 43 an opening 49 having two flat sides for insertion of the opposite end of tube 23. A yoke 43 is placed over the circular opening 41 (left side of Figs. 5 and 6) and against which a spring pin 52, provided in the tube 23, strikes. On mounting the attachment the tube 23 is first inserted through the opening 41 and the spring 44 compressed by means of the pin 52 until the other end of tube 23 can be inserted in the opening 49a. At the same time the spring 26 is tensioned by When the flat member 48 is inserted in the corresponding opening of support 46 (Fig. 7a) whereby the rod 49 is rotated by the key or wrench 28 against the action of the spring 28, the latter then exerts a rotational pressure in the clockwise direction and presses the small wheel I5 constantly against the platen I. The pin 52 and spring 44 operate as a bayonet closure.

Fig. 5 shows a tube 23 which at its right hand end is provided with a stud 49 having two flattened portions 49a. said stud being rigidly connected to the tube. These flattened portions 49a. (Fig. 7a) fit in an opening on the frame 46 of the machine. The stud 49 is adapted to be engaged by the key 28. When the apparatus is to be mounted upon the typewriting machine, the friction rollers i5 are applied against the typewriter platen l and the tube 23 turned by means of key 28 until the stud 49 is able to enter the opening in the frame of the machine. The tube 23 has a flattened end 230. in each of the housings 22 (Fig. 2), each of the flattened edges bearing against a leafspring 26.

When the tube 23 is turned, the leaf spring 26 will become compressed by the aforesaid flattened edges so that the spring tends to impart a rotary movement about the axis of the tube 23, to the housings 22 and hence also to the friction rollers 15 when the apparatus isapplied to the typewriting machine. Consequently the leaf spring 26 serves to press the friction rollers l against the platen. The tube 23 is fastened rigidly onto the frame of the machine and the housing 22 can be rotatably displaced on the tube 23.

The sheets to be typed are inserted in the usual manner with the additional ribbon swung out of the writing position. The original sheet is placed under the ordinary ribbon and over the additional ribbon, while the copy sheet is placed under the additional ribbon. A second copy sheet, on which the typing appears, or a protective sheet preventing contact with the original, may be placed between the original and the copy sheet. Each forward movement of the platen acts through the friction drive to advance the ribbon longitudinally of the platen hence new sections of the ribbon are continuously presented to the type until the end of the ribbonapproaches and necessitates a reversal of the direction of ribbon travel. This is, of course, accomplished in the manner already described.

For manually actuating the accumulator spring 38 there is provided a knob 5| the shank of which extends through a slot 50 in the housing 6 and is connected rigidly with the impact member 35. The shank of the knob 5| has sufficient play in slot 50 so that the knife edge 36 can be removed from the groove in worm 3'! by pressing the knob downwardly. By moving the knob 5| laterally in the slot 50, the knife edge 36 is likewise moved laterally and can be re-inserted in the worm groove, with the spring in its left hand position of Fig. 4, that is with spring 38 tensioned.

The two housings 6, for the ribbon carriers 3a and 3b, the power accumulator mechanism 35 to 40, the pawls I2, I 3, M for preventing slack in the additional ribbon and the upper paper guide rollers 9, Hi, i l are attached, are rigidly connected with each other by a rotary tube 53 slid over the fixed tube 23.

The advantages of the improved device are obvious without further explanation.

What I claim is:

1. A typewriter attachment for producing du plicate ribbon copies adapted for attachment to a typewriter having a platen, said attachment comprising a ribbon, ribbon-carrying means in the form or a tube adapted to be mounted on the typewriter and capable of being swung into and out of writing position with respect to the typewriter platen, a shirt bar axially slidable in said tube to change the direction of travel or said ribbon, friction driving means urged into driving relation with the platen of the typewriter, and means comprising a pair of leaf springs mounted in said tube for urging sair friction means into driving relation with said platen, said friction means being eflective when said ribbon is in both its writing and retracted positions.

2. A typewriter attachment for attachment to a typewriter having a platen for making duplicate ribbon copies, comprising a ribbon, ribboncarrying means adapted for mounting on the typewriter to bring the ribbon into operative relation with the typewriter platen, friction means driven by said platen for driving said ribboncarrying means, and axially slidable means comprising a bar for changing the direction of travel of said ribbon.

3. A typewriter attachment to be attached to a typewriter having a platen for making duplicate ribbon copies, comprising a ribbon, a pair of ribbon carriers, means for mounting said carriers one at each end of the typewriter platen, a tubular support, means including a bar axially slidable in said support for changing the direction of travel of said ribbon, a second tubular support surrounding said tubular support, ribbon carrier housing means carried by the ends of said second tubular support, and power storage means for actuating said bar from one of its positions to the other.

4. A typewriter attachment for attachment to a typewriter having a platen for making duplicate ribbon copies, comprising a ribbon, a pair oi ribbon carriers, means for mounting said carriers one at each end of the typewriter platen, a tubular support, means including a bar axially slidable in said support for changing the direction of travel of said ribbon, power storage means comprising a spring to move said bar from one of its positions to the other to change the direction of travel of said ribbon, a rotatable worm, an impact member having a knife edge for engaging the thread on said worm, said impact member engaging said spring and placing said spring under stress as said impact member moves under the influence of said worm and knife edge to store the energy required for moving said bar.

5. A typewriter attachment for use with a typewriter having a platen for making duplicate ribbon copies, comprising a ribbon, ribbon-carrying means for operative association with the typewriter platen and movable into and out of operative position, friction drive means actuated by the platen to move the ribbon, a ratchet wheel mounted for rotational movement with the ribbon-carrying means, a pawl having two positions in the first of which it engages said wheel to prevent said friction means from actuating the ribbon and in the second of which it is disengaged from said wheel to permit movement of the same, and means for causing the pawl to assume its first position during backward movement or the platen, the engagement of the pawl with the platen causing it to assume said second position during forward movement or the platen.

- JOSEFINE ROSA GESER. 

